Upward acting or vertical opening sectional doors are ubiquitous as residential garage doors and are also widely used in commercial door applications. There has been a continuing need to provide improvements in sectional doors of the general type referenced herein. One pressing need has been to reduce the weight of the door, particularly for doors used to close over openings in residential or commercial multi-car garages. These doors typically range in widths from eight to twenty feet and have a height of about seven feet. It is desirable to minimize the weight of the door while not sacrificing its strength and rigidity to provide a suitable secure insulated or noninsulated closure over the garage vehicle entry. In this regard extrudable or moldable polymer materials have been given consideration for use as the main structural members of doors. However, the use of these materials with other door support components has posed certain problems with respect to providing adequate strength of the door sections and accommodation of thermal expansion and contraction of the polymer materials as compared with metal door structural components or door structural components of other materials used in conjunction with the polymer materials. Moreover, it is desirable to provide a door structure which can be easily modified to include substantial or minimal thermal and/or acoustic insulation.
Another problem associated with the development of sectional vertical opening doors as well as other doors which utilize multiple door sections or panels which are hinged to each other is the development of a suitable hinge structure which can be an integral part of the door structural members and providing a long operating life, particularly with minimal or little maintenance, is adapted to minimize injury, such as by being configured to substantially prevent placement of a person's finger or fingers between the do or sections during pivotal movement thereof, provides a suitable light seal and weather seal, and provides for assembly of the door sections laterally with respect to each other instead of requiring a longitudinal end-to-end sliding fit of the door sections with respect to each other in order to assemble the hinge.